Further studies on the mode of action of the heme-controlled translational inhibitor.
- 1 April 1979
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 76 (4) , 1741-1745
- https://doi.org/10.1073/pnas.76.4.1741
Abstract
We have isolated [de Haro, C. & Ochoa, S. (1978) Proc. Natl. Acad. Sci. USA 75, 2713-2716] a protein factor (eIF-2 stimulating protein, ESP) that is essential for formation of ternary and 40S initiation complexes by the eukaryotic polypeptide chain initiation factor 2 (eIF-2) at the low concentrations of eIF-2 present in reticulocyte lysates. The fact that stimulation of complex formation by ESP is virtually abolished when the small (38,000 daltons) subunit of eIF-2 is phosphorylated by ATP in the presence of eIF-2 kinase (heme-controlled inhibitor, HCI) is consistent with the notion that HCI inhibits translation in lysates by blocking the interaction of eIF-2 with ESP. Our present work, with highly purified eIF-2 and ESP, has additionally established that, unlike phosphorylation of the small subunit, phosphorylation of the middle (52,000 daltons) subunit of eIF-2, which does not lead to translational inhibition in lysates, does not affect eIF-2-ESP interaction. This provides further support for our model of translational inhibition by HCI.Keywords
This publication has 21 references indexed in Scilit:
- Mode of action of the hemin-controlled inhibitor of protein synthesis: studies with factors from rabbit reticulocytes.Proceedings of the National Academy of Sciences, 1978
- Regulation of protein synthesis: Activation by double-stranded RNA of a protein kinase that phosphorylates eukaryotic initiation factor 2Proceedings of the National Academy of Sciences, 1978
- Effect of hemin on site-specific phosphorylation of eukaryotic initiation factor 2.Proceedings of the National Academy of Sciences, 1978
- Mode of action of the hemin-controlled inhibitor of protein synthesis.Proceedings of the National Academy of Sciences, 1978
- Binding and release of eukaryotic initiation factor eIF-2 and GTP during protein synthesis initiation.Proceedings of the National Academy of Sciences, 1978
- Phosphorylation of eukaryotic protein synthesis initiation factors.Proceedings of the National Academy of Sciences, 1978
- Role of 3':5'-cyclic-AMP-dependent protein kinase in regulation of protein synthesis in reticulocyte lysates.Proceedings of the National Academy of Sciences, 1977
- Regulation of protein synthesis in reticulocyte lysates: phosphorylation of methionyl-tRNAf binding factor by protein kinase activity of translational inhibitor isolated from hemedeficient lysates.Proceedings of the National Academy of Sciences, 1976
- Specificity of the protein kinase activity associated with the hemin-controlled repressor of rabbit reticulocyte.Proceedings of the National Academy of Sciences, 1976
- PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENTJournal of Biological Chemistry, 1951